Processing and Storage Effects on Berry Bioactives

1. Processing and Storage Effects on Berry Bioactives Luke R. Howard, Ph.D .

2. Phytonutrient/Phytochemical Components in a plant based diet other than traditional nutrients that can reduce the risk of degenerative diseases

3. Berries and Health Promotion Prevention of Chronic Diseases CHD & stroke Cancer Neurological disorders Obesity Type II diabetes Mechanisms Antioxidant Anti-inflammatory Cell signaling Gene regulation Apoptosis Modulation of enzymes

4. Free Radicals

5. Antioxidants

6. Fruit and Vegetable Phytochemicals • Fruit and vegetable phytochemicals play an important role in health-promotion • Due to limited shelf-life and seasonal availability, fruits and vegetables are commonly consumed in various processed forms • How does processing impact phytochemical content?

7. Flavonoids

8. Procyanidins Epicatechin Procyanidin B2

9. Anthocyanin-Procyanidin Polymers a.k.aPolymeric Pigments

10. The Problem • Phytochemicals losses are inevitable during fruit and vegetable processing • Losses are due a number of processing, biochemical, and food matrix factors • Losses can also occur during storage of processed products

11. Processing Factors Influencing the Stability of Phytonutrients • Temperature (blanching and pasteurization) • Light • Oxygen • Water (washing, soaking, canning) • Physical removal of tissues

12. Thermal Degradation of Anthocyanins

13. Strawberry Puree Stored One Month at 25oC

14. Biochemical Factors Influencing the Stability of Phytonutrients • Co-factors • Metals • Enzymes • pH • Ascorbic acid

15. Consequences of Cell Disruption PPO O2 PPO/POD POD + o-diphenols quinones ACY Phenolics Organic acids Sugars ascorbic acid degradation products ACY tannins + ACY mediators? polymers O2 tannins polymers ACY tannins ACY

16. pH Effect on Anthocyanin Structure

17. Food Matrix Factors Influencing the Stability of Phytonutrients • Chemical structure/solubility • Tissue localization: Free vs. bound • Interactions among compounds

18. Light Microscopy of Cranberry Pomace Differential interference contrast (DIC) microscopy image of residue remaining after ground cranberry pomace was extracted with acetone:water:acetic acid (70:29.5:0.5) and stained with dimethylaminocinnamaldehyde (DMAC) at 20x magnification Differential interference contrast (DIC) microscopy image of residue remaining after ground cranberry pomace was treated with 2 N NaOH at 60 °C for 15 m and stained with dimethylaminocinnamaldehyde (DMAC) at 20x magnification

19. Procyanidin Oligomer (DP1 – DP6) Composition of Cranberry Pomace Before and After Treatment with Sodium Hydroxide

20. Properties of Phytonutrients in Plant Tissues

21. Changes in Antioxidant Activity as Affected by Heating Nicoli et al. (1999) Trends Food Sci. Tech. 10:94-100

22. Food Matrix Interactions – Anthocyanin Co-pigmentation Intermolecular copigmentation Self-association Metal complexation Intramolecular copigmentation Aglycone Sugar Copigment Acid

23. Food Matrix Interactions – Binding of Procyanidins to Cell Wall Polysaccharides Le Bourvellec et al. (2009) Carbohydrate Polymers 75:251-261

24. Food Matrix Interactions – Binding of Procyanidins to Proteins Haslam (1998) Practical Polyphenolics: From structure to molecular recognition and physiological action. Cambridge University Press

25. Case Study: Processing Effects on Blueberry Polyphenolics

26. Case Study I Objectives • To determine how different preservation methods (canning, pureeing, juicing) affect the retention of blueberry polyphenolics and antioxidant capacity • To determine how storage of processed products affects the retention of blueberry polyphenolics and antioxidant capacity

27. Fresh Blueberries (cv. Bluecrop) Analysis of Fresh Berries Frozen Berries Individually Quick Frozen (IQF) Baking Juice Puree Canning Canned (Syrup) Canned (Water) Non-Clarified Clarified Pie-Canned in Water Pie-Frozen Berries Sampling: 1 d, 1 mo, 3 mo, 6 mo

28. Juice Processing Steps

29. Chemical Analysis • Polyphenolics (anthocyanins, procyanidins, chlorogenic acid, flavonols) measured by HPLC • Antioxidant capacity: ORACFL assay • Polymeric color: Colorimetric assay, measures the amount of anthocyanin polymers

30. Polymeric Color Assay

31. Total Anthocyanin Retention and Polymeric Color in Blueberry Juices % Retention % Polymeric color

32. Total Anthocyanin Retention and Polymeric Color in Canned Blueberries % Retention % Polymeric color

33. Total Anthocyanin Retention in Blueberries Canned in Syrup % Retention

34. Total Anthocyanin Retention and Polymeric Color in Blueberry Puree % Retention % Polymeric Color

35. Total Flavonol Retention in Blueberry Juices % Retention

36. Total Flavonol Retention in Blueberries Canned in Syrup % Retention

37. Total Flavonol Retention in Blueberry Puree % Retention

38. Total Procyanidin Retention in Blueberry Juices % Retention

39. Total Procyanidin Retention in Blueberries Canned in Syrup % Retention

40. Total Procyanidin Retention in Blueberry Puree % Retention

41. Chlorogenic Acid Retention in Blueberry Juices % Retention

42. Chlorogenic Acid Retention in Blueberries Canned in Syrup % Retention

43. Chlorogenic Acid Retention in Blueberry Puree % Retention

44. ORACFL Retention in Blueberry Juices % Retention

45. ORACFL Retention in Canned Blueberries % Retention

46. ORACFL Retention in Blueberry Puree % Retention

47. Dietary polyphenols Tissue metabolites Tissues Small intestine Liver bile Kidney Colon Urine Microbial metabolites Feces

48. Discussion • Which processing, biochemical, and food matrix factors most likely played a role in polyphenolic losses during processing and storage of blueberry products? • Why does the antioxidant capacity of stored products change little during storage despite losses of anthocyanins and procyanidins?

49. Discussion Continued • What steps can processors take to minimize phytonutrient losses during processing and storage? • What steps can consumers take to minimize phytonutrient losses following purchase of processed berry products? • Would you expect processed berry products to have the same health benefits as fresh berries?